Washington, Jan 14 : Analysis of the chemical composition of 635-million-year-old rocks from the Norwegian island chain of Svalbard has revealed oxygen trapped inside the rocks, which suggests ancient Earth once had an alien atmosphere that might have helped melt millions of years' worth of deep freeze.
According to a report in National Geographic News, the analysis shows a surprisingly low amount of a particular type, or isotope, of oxygen.
Reduced levels of this isotope are linked to high levels of carbon dioxide in the atmosphere, and the new data suggest ancient Earth might have had 300 to 1,000 times more CO2 than current levels.